Development and dissemination of evidence-based mental health treatments depend on valid and reliable assessment of treatment outcomes in the full range of practice settings and patient populations. However, many instruments developed for clinical efficacy research are not feasible for effectiveness research and outcomes management. Simply, measures that are confusing or overwhelming cannot measure outcomes accurately. Research applying theories and methods of cognitive science in attitude and opinion measurement has produced models of the measurement process, empirical evidence of cognitive difficulties that limit measurement quality and methods for detecting and minimizing these difficulties. These methods hold great promise for improving mental health outcome measures. This Mentored Research Scientist Development Award is designed to meet near-term career goals of using cognitive strategies to improve mental health outcome measures and long-term career goals of designing and conducting more informative treatment outcome studies. The career development plan sets three goals: (1) To develop knowledge based in cognitive science, (2) To develop expertise in applied cognitive methodologies and (3) To develop skills in qualitative data analysis, to be met using six development activities: mentoring from application sponsors, course work, conferences, directed study with expert advisors, collaboration with local mental health services researchers, and a research plan that builds cumulatively on knowledge and skills gained though career development activities. The research plan addresses four specific aims: (1) Develop hypotheses about cognitive difficulties and response effects in mental health outcome measures, (2) Examine hypothesized response effects through analyses of existing outcome data, (3) Test and compare cognitive evaluation and interview methods for identifying and understanding cognitive processes that lead to measurement problems, (4) Pilot methods for developing and testing improved measures designed to correct cognitive difficulties and response effects.